The electrical grid in the United States, or in any developed nation or continent for that matter, is the power industry's electrical network which essentially organizes four critical operations, (1) electricity generation, (2) power transmission, (3) power distribution and (4) electricity control. The “grid” can also refer in certain instances to a regional electrical network or even a local utility's transmission and distribution grid.
Electricity generation is traditionally accomplished by large generating plants such as nuclear reactors, hydro-electric dams, coal and gas fired boilers. The electric power which is generated is stepped up to a higher voltage—at which it connects to the transmission network. The transmission network will move, i.e. “wheel”, the power long distances until it arrives at a local utility distribution network, where at a substation, the power will be stepped down in voltage—from a transmission level voltage to a distribution level voltage. As it exits the substation, it enters the distribution network. Finally, upon arrival at the service location such as a residential home or commercial user, the power is stepped down again from the distribution voltage to the required service voltage(s).
The traditional grid, along with its regional distinctions, are currently subject to the introduction of more efficient and smarter, although often smaller power generation technologies. Regional and local grids are now subject to low level dispersed power generation from regional large and small wind applications, small hydro-electric facilities and even commercial and residential photovoltaic installations for example. As such regional and local power producers come on-line the characteristics of power generation can in some new grids be entirely opposite of those listed above. Generation may occur throughout the grid at low levels in dispersed locations. Such characteristics could be attractive for some locales, and can be implemented in the form of what is termed a “smart grid” using a combination of new design options such as net metering, electric cars as a temporary energy source, and/or distributed generation. The modular power conversion system described below is an example of at least a portion of the developing “smart grid” technology.